In nonvolatile semiconductor storage devices, bit lines are disposed within a memory cell region with a predetermined spacing from one another. The bit lines are connected with contact plugs.
In the above described arrangement, lithography misalignment or the like occurring at the connection portions of contact plugs and bit lines may close the distance between the contact plug and the bit line disposed adjacent to the bit line to which the contact plug is supposed to contact. The distance between the contact plugs may also be closed by lithography misalignment or the like. Such closing of distance, or the like, between the contact plug and the adjacent bit line may lead to increase in leakage current.